Signors to the firm of fried



' zsheets-sheet 1,- A. SCHMITZ 8u E. EHRENSBERGER. PROCESS 0F MANUFACTURING ARMOR PLATES. No. 534 178.

.'/f [//ay/ :ff/4%.

' (No Mode-1.)

2 sheets-sheet 2.V A.` SCHMITZ 8u El' EHYRENSBERGER. PROCESS OFMANUPAGTURING ARMOR PLATES. No. 534,178.

(No Model.)

Patented Feb. 12, 1895.

Wnses:

1mm@ r m n n. A n WE .A1

i vm.

E Nonms Pneus co. Puma-Ln UNITED FSTATESYPATENTv "EEICE,

Y ALBERT SCHMITZ AND EMIL EHRENSBERGER, oF ESSEN, GERMANY, AS SIeNoRSTo THE FIRM oE FRIED. KRUPP, or SAME PLACE.

PRooEssl` oF MANuFAoTURiNG ARMOR-PLATES.

SPECIFICATION forming .part of'Letters Patent No. 534,178, dated February 12, 1895.

Application sled reentry 24, 1393. serial No. 45 9,563. ANotaalgrens.iA Patented in Germany Number 16,1892,N0s.72,547 and 74,242; in France December 9, 1892,`No. 226,286; in Belgium December 10, 1392, No. 102,523; in England December 16,1892,N0. 23,228; in Italy December 31, 1892, XXVII, 33,126, LXV,104. and 1n spain retmry 9, 1893,110. 14,054.

' Prussia, residing at Essen, in the Kingdom of Prussia, German Empire, have invented new ,and useful Improvements in Processes of and Apparatus for or Relating to the Manufacture yof Armor-Plates, (for which we have obtained Letters Patent in Germany, Nos. 72,547 and 74,242, dated November 16,1892', in France, No. 226,286, dated December 9, 1892; in Belgium, No. 102,523, dated December 10, 1892; in Great Britain, No. 23,228, dated December 16, 1892; in Spain, No. 14,054, dated February 9, 1893, and in Italy, Reg. Gen., Vol. XXVII, No. 33,1 26, Reg. Att., Vol. LXV, No. lO-l, dated December 3l, 1892,) of which the following is a specification. A

It is known'that iron deficient in carbon can be very quickly carbnreted .by passing hydrocarbon gases over the same, and according to our invention we utilize this knowledge as hereinafter described for the purpose of giving a hard surface to one face of otherwise soft armor plates of all kinds. Y Our invention will be readily understood from the following description having reference to the accompanying drawings, in which l l y Y Figure 1 is a vertical, longitudinal section of a furnace adapted for carrying out our process. Fig. 2 is a transverse section and Fig. 3 is a horizontal section of the same fur- Similar letters of reference designate corresponding parts. v

The furnace A is heated by gas which enters through the passage a, while the air is suppliedthrough thepassage b. The products of combustion escape through two passages c that are situated on either side of the door d. The'hearth B of the' furnace is capable of being drawn out from the latter, say on rails as shown. The first plate C to be carbureted-is laid with the'face to be carbureted uppermost, upon supports or pillars e on the hearth of the furnace, the said hearth having beenvdrawn out of the said furnace, while a second plate D is laid with the face tobe carboniz'ed, toward the first plate and is held at a small distance from the latter by means of intermediate pieces of iron j", stone or other suitable material. When so placed both plates have walls g g h 2' built round them, so that the space between the two armor plates is completely closed with the exception of two vholes 7c in the wall h and two larger holes Zin the wall ,while the furnace gases can pass freely above and below the exterior surfaces of the respective plates, the gases passing under the plate C through openings m formed in the walls h and i. have been built up in this manner on the hearth, the latter is pushed into the furnace and the latter is heated, until the plates are at about the melting temperature 'of copper. whereupon pipes fn and o, the positions of which are indicated at Fig. .1, are passed through two openings in the furnace door into the holes Zin the wall rl, and hydrocarbons, illuminating gas, paraffine-vapor, petroleumgases, or-fthe like, are passed through said pipes in between the plates. The surfaces of the plates become carbureted by the action of these gases in acomparatively short time, while the used gases deprived of a large proportion of their carbon, pass through the openings lc into the wall h in the furnace and-burn there. As soon as the carburization of the plates has reached the desired degree, the hearth is run out and the plates are hardened by dipping into or by spraying the parts to be hardened, with water or oil.

The same arrangement as employed, according to our invention, for carbureting with hydrocarbon, may be also employed for carbureting with solid carbon or the like, by merely fitting with the same the space between the two armor plates into which the gas would otherwise enter. The holes 7c and l, and the supports between the plates, are dispensed with in this case. This method of hardening two plates together with solid carbon is an important improvement on the heretofore usual method of carbureting one plate only at a time.

The faces of the platesg exposed to the frame are in both methods vpreferably pro- After the two plates tected by a light suitable covering of [ire clay or the like.

Having now particularly described and ascertained the nature of our said invention and in what manner the same is to he performed,

n We declare that what We claim is l. The described process of cementation of l plates or articles to be carbonizedon-one sidek only, said process consisting iu forming in a furnace a gas-tight chamber or inclosure having the surface of the plate to rbecemented for a portion ofthe Wall thereof, heating the plate and admittingto said chamber gaseous f cementing agents, substantiallyas setvforth."

2. The herein described process for the manufacture of armor. plates, ds c.,-hardened` on one side only, consistingtin buildingfthe same into a furnace with the faces to be hard-y ened opposite'to each other and Withantintermediate space, heating said plates,then

` admitting a gaseous hydro-carbon into the in` closed space and discharging the used "gases deprived of alarge proportion of their carbon.

3. yThe herein described process for the manufacture of armor plates, &c. hardened on one side only, consistingin building the same into a furnace with the faces to be hard# ened opposite to each othern and with alainn terniediate space, heating` said plates, then passing a gaseous hydrocarbon into the inclosed space, and finally hardening, suhstam tially` as described.

4; The herein described process for the p manufacture of armor plates, &c. hardened on one` side only, consisting in building the same into a furnace with the facesto be hardu manufacture of armor plates hardened on one side only, consisting in building saidtplates y o y intera furnaceWithithefaces.toibe hardened opposite to each other and an intermediate f space; heatingsaid plates while infcontact u with carbonaceous matter Killing said interme 5o `:the `furnacaand hardening."` f

In testimony-whereof "wehave signed `our `names to thisspecication' inthe presence of` two subscribing witnesses.'

ALBERTQSGHMITZ.' EMILn EI-IRENSBERGER.

lVitnessesz,` n n ALBERT KLINGHAMMER, CHRISTIAN SORMENREHEIN.

` diatfspace and then removingthe plates from 

